My air stopped being cold in 100 degree heat… the perfect time.
I can barely stand it anymore I generally spend a couple hours in my car per day, now theyre unbearable.
How much should I expect to fork over to get my freon charged and my AC working again?
How much greatly depends on:
Is it REALLY R-12 freon, or R-134a (The newer, greener stuff)
Further, it also depends WHY the refrigerant went away. The right procedure will:
Conversion from R-12 to R-134a can be less expensive than just charging with R-12, but you’ll lose some cooling effect. There will be a sticker somewhere obvious in the engine compartment.
10 odd years ago I needed a new compressor, full system flush, and conversion to R-134a…IIRC it was about $700.
Now, if you just need a top-off and a new switch, it could be under $100.
I drive a 99 alero, if that tells you anything.
And I drive a '93 honda and am having the same problem.
I can probably find the system size in my reference programs at work tomorrow if you are curious.
I work in LA at a import specialty shop we charge $100 for the service, about $10 for compressor oil and $1.57/ oz for R-134.
Usually works out to about $140-160 on a Volvo.
Any leak repairs would be additional.
But how much would you charger to fly out here to North Carolina 
Fact of life, AC systems leak. The newer the system the less they leak, but they all leak. The newer the car the tighter the system from both an aging point of view and from a design point of view. (many new cars now have multiple seals on each connection, older cars only had one seal)
As the refrigerant leaks out system performance degrades. At some point the customer notices it, and wants it fixed.
Of course any leak in the system will accelerate this degradation.
You can also have a loss of cooling from a catastrophic failure, such as a broken hose, or dead compressor.
melodyharmonius I would love to come to North Carolina eat some good barbecue and fix your AC, but frankly for what it would cost to ship both me and my recycling machine, you can do it for less locally. 
is there any posibility that the ac may lose the ability to cool due to some other problem the freon or a leak?
Sure. Electrical problems related to the compressor, a defective low pressure cutoff switch (if present), defective compressor clutch. Hence the need to pay for diagnostics.
Yes, a bunch of reasons. In no particular order (and off the top of my head):
[ul]
[li]Cooling fan inop[/li][li]Bad fan clutch[/li][li]Compressor clutch dead[/li][li]Collapsed hose[/li][li]smashed pipe[/li][li]Bad expansion valve / orifice tube[/li][li]Condenser matted with dog hair (Yup I had one of these)[/li][li]Belt missing off of compressor[/li][li]Moisture in system[/li][li]Compressor grenading internally[/li][li]Blown fuse[/li][li]Bad relay[/li][li]Bad control module[/li][li]Car over heating[/li][li]Other sensor input to the Engine Control module out of range preventing AC operation to be given the OK[/li][li]Wiring fault[/li][li]Bad switch[/li][li]Overcharge[/li][li]Bad pressure switches (both low pressure and high pressure cut out)[/li]
[/ul]
Wnat me to go one?
Yep, I just spent 440 USD on air conditioning repair. 99 Ford escort with 130,000 miles. It turned out to be some bad relay behind the control panel.
I Should add that I trust these guys. They make a real effort and they know enough about cars that they don’t treat me as a moron.
And Rick? How in the hell do you take apart a modern car dashboard? No details needed but I’ve always wondered.
So if I had a problem with my car overheating last year - that could have possibly snafu-ed my AC? Bet that’s not an easy fix.
My plan has been to just suffer through the summer without it because I hope to buy a new car next year or so, but this heat has got my re-thinking things.
Doubtful. The A/C system is pretty seperate from everything else. If it’s sealed, and the compressor is spinning, and the HVAC controls are working, it just works.
In MOST situations, the AC shouldn’t affect your car overheating, but it IS rejecting heat to an area right next to your radiator (think of your A/C as a heat pump, it’s moving heat from the inside of your car to the condenser, with 99% of the time is in front of the radiator.) If your radiator isn’t working due to external or internal blockage, you may see the needle change when you have the A/C on or off, but that’s due to deficiency of your radiator.
(YMMV, this assumes a properly sized and functioning AC system.)
As soon as the cause of the overheating was corrected, the AC would return to full functionally. In the case of a dead cooling fan, oft times one of the first symptoms is poor AC operation, even before the temp gauge starts to climb.
So if you are thinking this is some residual from last years overheating, I doubt it.
gravitycrash dashes are a royal pain the ass to work around. Some stuff you access from below, or maybe through the glove box. For other stuff the easiest way is to pull the entire dash as one giant unit. On some cars this is a snap. On others, it is hours of labor.
That statement brings back memories of helping a buddy roll the dash out of his classic Mercury Cougar to get at and replace the inoperative mechanical clock. It was an all day job, and by the time we had the dash in our laps, he swore we’d never get the sumbitch back together again. Much swearing and a few beers later, we did, though. 
Very carefully.
It really, really helps to have a shop manual and a highly-developed sense of mechanical intuition. Depending on what you need to get at, and what kind of car it is, you may need to start at the back seat and work your way forward to remove the parking brake, shifter and center console to get at the One. Danged. Screw. That. Holds. The. Gol. Darned. Radio. That. Is. Hiding. The. One. Last. Bolt.
Other times, you might not need to do anything more than open the glove box, reach back and disengage a catch to remove the glove box, and your target thing is right there.
And then, there’s always the time that you have serious thoughts of finding a five year old kid, give them a screwdriver, and invite them to crawl up between the pedals.
And heaven help you if you need to get at the heater core. The old joke is that the heater core is the first thing rolling down the assembly line, and everything else is bolted to it, working outward.
It takes me approximately 10 minutes to disassemble the dash on a '01-'05 Hyundai Elantra, FWIW (not including the handbrake assembly and surround).
There’s a product called Red Tek, which contains no freon, but apparently works better than freon.
S^G
I strongly recommend using ONLY R-12 or R-134a (correctly chosen for the application) in automotive A/C systems. Every substitute proffered has some drawback, which of course the vendor is not going to be telling you about. NO SUBSTITUTES AT ALL ARE APPROVED BY CAR MANUFACTURERS OR A/C PARTS MANUFACTURERS, and with good reason. For example, blends tend to separate and not function properly, R-22 decomposes seals, hydrocarbons are flammable, etc. Use of a substitute can screw something up and cost more in the long run than getting the right stuff.
Red Tek is essentially hydrocarbons, alkanes. While propane is used as a refrigerant in certain stationary systems where it can be reliably contained and the risk of ignition is extremely low, as you can imagine cars present quite a different environment. The risk of EXPLOSION is not insignificant.
Furthermore to legally use such a product, there has to be warning labels attached to the car, and you can NOT use either R-12 or R-134 fittings. The fitting must be unique to prevent cross contamination of the recycling equipment at the repair shops.
Adding to that, most shops will [del]toss your ass out[/del] refuse to work on your car since they probably don’t own a dedicated recycling machine for the snake oil de jour.
I know I would.